1. Field
The present disclosure relates to a fuel injection device having a fuel injection valve that injects fuel directly into a combustion chamber of an internal combustion engine and, in particular, to a fuel injection device having a step-up circuit that steps up an output voltage of a battery for driving the fuel injection valve.
2. Description of the Related Art
The related art discloses a fuel injection device having a fuel injection valve for injecting fuel directly into a combustion chamber of an internal combustion engine and a step-up circuit for stepping up a battery voltage (see, for example, Japanese Unexamined Patent Application Publication No. 2014-9627). The step-up circuit includes an inductor, a switching element, a diode, and a capacitor, in which the switching element is switched on and off to step up the voltage of the capacitor and output a stepped-up voltage.
During an operation of an internal combustion engine, a capacitor of a step-up circuit is applied with a voltage of around 40 V, for example, and charge is accumulated therein. Although an ignition switch is turned off, the charge accumulated in the capacitor is not immediately dissipated, and it takes several tens of minutes before the charge is fully dissipated. Therefore, when it is necessary to start a maintenance operation within a relatively short time after the ignition switch is turned off, for example, electric shock of an operator needs to be prevented.